Many "free new download" links found on forums or YouTube descriptions are often bundled with or require risky "keygens". Printer Damage:

V5204 is an updated version that supports a wider range of modern printers than older tools like V3400, including high-end models like the Critical Risks and "Free" Downloads

Canon Service Tool v5204 is a specialized maintenance utility used primarily by Canon service center technicians. While it is highly effective at resetting waste ink counters and performing deep maintenance, the "free" versions circulating online come with significant caveats regarding safety and hardware compatibility.